The present invention relates generally to a device for installing aerial electrical power lines and in particular to a device that manages ropes and cables during the installation process.
Residential homes typically have three conductors entering the building from the street utility electric lines. Two of the conductors are power conductors each carrying a single phase of electricity. Meaning the waveforms of the electricity on the two conductors are typically out of phase by 180 degrees. The third conductor entering the building is what is known as a neutral phase, which connects to earth ground. While the neutral may carry current, it normally will have no electrical potential or voltage. Each phase of the power conductors connects with one branch of 120V circuits within the building. Where 240V is required, for a stove or electric clothes dryer for example, both power conductors are used for that circuit.
The conductors extend from the residential homes through an electrical distribution network to substations that typically transition to a high voltage transmission network. In addition to the conductors, the distribution network may include further equipment, such as transformers, switches, circuit breakers and other devices that assist in the control and delivery of electrical power. The conductors may be positioned either underground, or more commonly above ground, suspended from poles that may also be used for routing other utilities such as telephone and television cables.
Placement of the conductors on utility poles provides a convenient routing of the conductors by allowing the area around the cables to be safely utilized while inhibiting vandalism for example. However, since the conductors are suspended 20 feet (6 meters) or more above the ground, it also presents some challenges when the conductors need to be installed. Conductors may be installed on a pole during several points in time, during initial deployment, in the event they are damaged by a storm or accident, or during upgrades of the network for example.
Since the weight of the conductors is too large for the conductors to be pulled directly, the installation process typically has several steps. First a rope is coupled to each pole where the conductor is to be installed. The opposite end of the rope is tied to a cable, such as a stranded-wire steel cable for example. The rope is then used to pull the cable up to suspension point on each pole. Finally, the end of the cable is tied to the conductor. Since the cable is strong enough to pull the conductor without breaking, the cable is used to pull the conductor up to the suspension point on the pole.
While the process for installing a single conductor is simple, the utility crew often needs to install multiple conductors to the same pole. The most common configurations involve a single 3-wire circuit, having three power conductors plus a neutral conductor, and two 3-wire circuits, having six power conductors plus a neutral conductor. Since the conductors are all installed at the same time, problems commonly arise due to the number of ropes and cables suspended from the pole. During installation the ropes need to be maintained in their correct order and spatial orientation, otherwise the conductors will cross. Since conductors are not allowed to cross, in the event a rope becomes tangled or crossed during installation, the ropes may need to be disconnected from the utility pole and reinstalled. This results in lost time and increased costs.
Correct installation becomes even more difficult in applications where the two 3-wire circuits are utilized since the utility crews typically only have ropes in four colors. To avoid incorrect installation, the utility personnel must be diligent in maintaining the ropes in the correct positions. Even when no mistakes are made, the increased diligence slows the process, which in turn increases time and cost.
While existing systems and methods for the aerial installation of electrical conductors are suitable for their intended purposes, there still remains a need for improvements particularly regarding the handling and securing of installation ropes to increase the speed and reliability of installation.